Improvement in screw-propellers



L C. BRUWNE.

Screw-Propeller.

Patened April'27,1875.

UNITED STATES PATENT OFFICE..

JOHN OOLLIS BROWNE, O F LONDON, ENGLAND.

IMPROVEMENT IN SCREW-PROPELLERS.

Specification forming part of Letters Patent N0. 162,619, dated April 27, 1875; application lod July 16, 1874.

To all whom it may concern:

Beit known that I, J oHN CoLLIs BRoWNE, of London, England, have invented certain new and useful Improvements in Propelling- Screws, of which the following is a specification:

My invention consists in the arrangement of two independent screws, or sets of blades, having their like faces reversed with respect to each other, as hereinafter described.

Figure l of the accompanying drawings is a front elevation of my improved propellingscrew. Fig. 2 is a side elevation of the same; and Fig. 3 is a perspective view, showing the screw applied to a vessel.

As shown in the accompanying drawing, a and b are the blades of the screw, which are, as represented,formed with a transverse curvature, so as to present on one side a concave surface and on the other a convex one. The blades taper from their centers to their extreme ends,which arepointed, andare curved slightly inward or toward the axis.

It will be observed that the blades are formed in pairs, and that each pair projects from a separate hub. The pairs are alike in form, but are relatively reversed in position on the shaft, or turned toward cach other, so as to present like faces in opposite directions, or unlike faces in the same direction, as shown in Fig. l, where it will be seen that the convex faces a a and concave faces b b point in the same direction, the concave faces of each pair of blades pointing toward or opposite each other.

It will be seen, on referring to Fig. 2, that one pair or series of blades is set fully before the other, so that each pair revolves in separate parallel planes.

M y improved arrangement and construction of blades result in an increase of speed, a sav-- ing of power, and an avoidance of the tendency ofthe common propeller to force the vessel to one side. It also avoids the vibrations produced by the common propeller, and secures equal efficiency in whichever direction the screw is rotated, thus enabling the vessels motion to be quickly checked and reversed, when desired.

I do not desire to limit myself to the use of my improved propelling-screw forl the propulsion of vessels only, as, by suitably arranging the same in connection with tubes or pipes, it may be used for the purpose of moving or lifting Water or other liquids, or for forcing 0r eX- hausting air or other gases. I also propose to employ it in the propulsion of balloons and other aerial machines, by mounting it on a shaft capable of universal motion, so that the propeller may be used to assist the balloon in its upward or downward movements, as well as moving it horizontally, by changing the direction of its axis.

I do not claim relativelyreversing the blades so that the acting faces are alternately convex and concave, as that is not original with me; but

VVha-t I claim as my invention is- The combination of the two sets of blades or independent screws a and b, having the like faces ofthe blades arranged in reverse order, substantially as shown and described.

JOHN OOLLIS BROWNE.

Witnesses:

H. GARDNER, E. M. DANIEL,

166 Fleet street, London. 

